Polyene Carboxylic Acids from a Streptomyces sp. Isolated from Tibet Soil.

Six new polyene carboxylic acids named serpentemycins E-J ( 1 - 6 ), together with three known analogs ( 7 - 9 ), were isolated from the fermentation medium of Streptomyces sp. TB060207, which was isolated from arid soil collected from Tibet, China. The structures of the new compounds were elucidated mainly on the basis of HR-ESI-MS and NMR spectroscopic analyses. The inhibitory activities of compounds 1 - 9 against NO production in LPS-activated RAW264.7 cells were evaluated. Compound 9 has an inhibition rate of 87.09% to 60.53% at concentrations ranging from 5.0 to 40.0 µM.